What the Heck is a Vegetated Swale?

It is simply a drainage ditch that is filled with dense and/or deep-rooted, water-loving native plants that will infiltrate rainwater instead of allowing it to move as fast as possible off the property to be dealt with by someone else.

Here are some examples:

This is the first vegetated swale I ever saw, many years ago, in the far west area of Batavia, designed by Kerry Leigh. Blazing Star (Liatris pycnostachya) and Yellow Coneflower (Ratibida pinatta) are in full bloom in July. The real workhorses of a vegetated swale are, however, the sedges. Sedges have dense root systems that hold water like a sponge; 1/3 of the roots die every year, providing channels that rain can infiltrate, drawing it deep into the soil. I don’t know which sedges have been used here, but Common Fox Sedge (Carex stipata), Brown Fox Sedge (C. vulpinoidea), and Narrow-leaved Cattail Sedge (C. squarrosa) are commonly used.

This vegetated swale is in the far west area of Elgin. Blue Flag (Iris virginica var. shrevrei) is in bloom in June. Sneezeweed, Ironweed, New England Aster, Swamp Milkweed, Queen of the Prairie, and Sweet Black-eyed Susan will bloom throughout the season. Sedges, especially Carex scoparia, are prolific.

Two downspouts emptied at the corner of this house and cut a narrow gully downhill through the lawn to the woods at the back of the house. I filled it with moisture-loving plants. Shown above are Cup Plant (Silphium perfoliatum) and Spotted Joe Pye Weed (Eupatorium maculatum).

An engineered swale on a parkway requires digging the soil out of the drainage area so the swale is a foot lower than the surrounding ground with inlets or curb cuts that let in the rainwater that falls on the street. In addition. the soil is dug out to a depth of 4’ and a plastic perforated pipe is installed at the bottom. The soil is replaced with an engineered mix of 70% course sand and 30% compost. These are simplified and condensed directions that I have taken from the blueprints of Trotter and Associates, the engineering firm that designed the vegetated swales for my neighborhood. I make no claims to engineering expertise.

The first swale was planted by our neighborhood group and other interested citizens from our town in the SWAN (South West Area Neighbors) neighborhood in September 2012.

Vegetated swale installed in the center of Spartan Drive, the entrance road to Elgin Community College campus. Blazing Star (Liatris pychnostachya) and Little Blue Stem (Schizachyrium scoparium) are apparent. Moisture-loving plants grow in the deeper center of the trench, while plants that require drier soils grow around the higher edge

Blazing Star is a stunning presence in the landscape in fall and winter in the vegetated swale at ECC.

Curb cut.

Stiff Goldenrod and Little Bluestem in vegetated swale at ECC in September.

Northern Kane County Wild Ones will be visiting these vegetated swales at ECC and in the SWAN neighborhood on Saturday, September 28 beginning at 10:00 AM at the ECC parking lot on the corner of Spartan and Lehr Drive. You do not have to be a member to attend.

11 Responses to What the Heck is a Vegetated Swale?

Nicely done!! Involving the neighborhood is the best public awareness you can do.
Also great before and after photos to show other neighborhoods how it was done and the great results you achieved. Bravo!

Oh my goodness, Pat. The progressive images of the neighborhood swale and the one at ECC in different seasons fascinates me. I keep looking and scrolling up and down. We have wet areas on our property and you’ve given me some useful info. I think we’ve been throwing the wrong seed in these places.

Four neighborhood swales? I think it’s a testament to your influence, Pat. What a great communal effort. I remember our prairie used to be called the Massion weed patch about 15 years ago. Now people come walking by to see what’s new and flowering.

The city of Elgin received a grant from the state of Illinois to do this. Sustainability has been a big part of Elgin’s mission for a few years now. They initiated a workshop 5 or 6 years ago run by Douglas Farr, author of Sustainable Urbanism, Urban Design with Nature. From that came an overall Sustainable Committee, with many sub-committees–I, of course, chose to be on Green Infrastructure. You can find all this at the City of Elgin’s Website.

There was a chapter in the book entitled Stormwater Systems written by Jim Patchett and Tom Price, both friends of mine, of Conservation Design Forum, located in Elmhurst. In that chapter, they recommended, among other things, bioretention services. This was presented to our neighborhood, slides were shown, and was enthusiastically endorsed. Many more will be built this fall.

But yes, I will give myself some of the credit, because everyone in my neighborhood had been exposed to seeing native plants growing in my parkways and were more than willing to have the same thing in their parkways.

If some of you blog readers don’t realize it, Pat as been honored by the City of Elgin for some of her efforts. I can’t recall the exact title of this “Green” award but SWAN and the entire city benefit when she shares her knowledge, expertise and passion for gardening, the environment and the planet. You go, Pat!